采用正交试验优化Cu-Ni-Sn合金的热处理工艺

采用正交试验研究了预变形量和时效处理对新配比Cu-Ni-Sn合金(固溶态Cu-Ni-Sn合金)的力学性能的影响,并使用正交极差分析法得出最佳工艺参数。结果表明,影响Cu-Ni-Sn合金硬度的变化因素为时效温度＞预变形量＞时效时间;影响合金抗拉强度的变化因素为预变形量＞时效时间＞时效温度;影响合金断后伸长率的变化因素为时效温度>冷变形量>时效时间。由此确定最佳的工艺为时效温度360 ℃,时效时间5 h,预变形量40%。随着时效温度和预变形量的增加,合金拉伸断口形貌由大量韧窝的韧性断裂转变为河流状形貌准解理断裂,再到冰糖状沿晶脆性断裂,表明合金塑性逐渐下降。

Optimum heat treatment process of Cu-Ni-Sn alloy by orthogonal test

Effect of pre-deformation and aging processes on mechanical properties of a new Cu-Ni-Sn alloy(in solid solution state)were studied by using orthogonal test,and the optimum process parameters were obtained by orthogonal range analysis.The results show that the factors affecting the hardness of the Cu-Ni-Sn alloy are:aging temperature>pre-deformation amount>aging time,the factors affecting the tensile strength of the alloy are:pre-deformation amount>aging time>aging temperature,and the factors affecting the percentage elongation after fracture of the alloy are:aging temperature>pre-deformation amount>aging time.Therefore,the optimum process is determined as:aging temperature 360℃,aging time 5 h and pre-deformation amount 40%.In addition,with the increase of aging temperature and predeformation,the tensile fracture morphologies of the alloy changes from ductile fracture with a large number of dimples to quasi-cleavage fracture with river-like morphologies,and then to intergranular brittle fracture,indicating that the plasticity of the alloy gradually decreases.